Your glucose, glowing quietly on the nightstand.
Cairn is a bedside dock that shows readings from your CGM's sharing service, lights a soft halo and sounds a chime when you're out of range, and charges your phone while you sleep. An extra alert you can hear across the room, alongside your CGM app's own.
Join the waitlistIn range: a faint warm glow you can sleep next to.
Look over, not up.
Checking your number at 3 a.m. shouldn't mean unlocking a bright phone. Cairn keeps the reading where your eyes already land, and lets the light tell you whether you need to look at all.
Readable from bed
A dim, dead-front display behind the stone's front edge shows the reading and trend arrow. Off pixels are truly black, so it disappears until it lights.
A halo you can hear
Light spills onto the nightstand from underneath, and a matching chime sounds when you're out of range. Colors differ in brightness and chimes differ in pitch, so you can tell them apart without looking.
Charges your phone
Set your phone on the flat top and magnets pull it into line over the charger, even in the dark. It rests behind the display, so it never covers your reading. Phones without magnets, or in thick cases, still charge. They just don't snap.
Cairn, in its own words.
Three 15-second spots, told by the dock. Turn the sound on to hear its chimes.
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Nightstand Operations
He swiped away two phone alerts. Cairn chimed the third, and it charged his phone anyway.
Music -
Night Shift
Lily pulls the plug at 11:42 PM. Cairn keeps chiming on battery and alerts Dad's paired phone down the hall.
On hold for public release until remote caregiver alerts ship.
Music -
Head of Communications
Cairn explains what each of its sounds means. One tap on the top quiets it. Urgent low takes two, which the cat learns the hard way.
Music
Draft cuts. The chimes are stand-ins until we can record a real dock, and captions and dock details will change before release.
See it. Hear it. Across the room.
When you're out of range, Cairn lights its halo and sounds a chime. Each state has its own color and its own sound, so you can tell them apart without looking. These are the defaults; you set the thresholds, volume and quiet hours in the Cairn app.
Tap the top of the stone to quiet a chime. The halo stays lit until you're back in range, and Cairn chimes again if you're still out of range later. There's no open-ended snooze.
Cairn is an extra alert alongside your CGM app's alerts, not a replacement. Keep your CGM app's alerts on. Readings can be delayed or unavailable if Wi-Fi or Dexcom Share is down. Not a medical device.
- In range
- A very faint warm white, barely there. Silent.
- High
- Steady cool blue, with a two-note chime that rises.
- Low
- Steady amber, with a two-note chime that falls.
- Urgent low
- Red with a slow pulse, and a pulsing alert that repeats until you tap the top of the dock twice. It always sounds, even in quiet hours.
- No recent data
- Dim white and a soft, level two-note chirp after 20 minutes without a new reading, so an old number never looks current.
It keeps going when it's unplugged.
Three AAA batteries in the base keep Cairn running through a power cut or a pulled cord. It plays a short unplug chime, shows "On battery", keeps reading and keeps its light and sound alerts on, and tells the phones paired with it.
The battery door takes a coin to open, so little hands can't quietly take the backup. If the batteries go missing or run low, Cairn shows a small icon and your phone reminds you once a day until they're replaced.
Unplug alerts reach paired phones within Bluetooth range of the dock. Alerts for caregivers away from home are planned for a later version.
Bedroom dock was unplugged at 11:42 PM. Running on battery.
Bedroom dock's backup batteries are missing. Replace 3 AAA batteries.
Set up in a few minutes.
No Cairn account. The app pairs with the dock over Bluetooth, hands it what it needs, and gets out of the way.
Plug it in
Cairn starts in setup mode and shows its name.
Pair with the app
Type the six-digit code shown on the dock into your phone.
Choose your Wi-Fi
Cairn joins your network and checks it can reach the internet.
Connect Dexcom Share
Sign in with the CGM wearer's account. Cairn shows the latest reading to confirm.
Name it
"Bedroom", "Mia's room". The name appears in alerts.
Four stones.
Every finish carries the quartz vein. Pictured colors are early renders and will change.
No Cairn cloud in the middle.
Cairn has no account. The dock fetches readings from Dexcom Share directly over your Wi-Fi, and nothing passes through Cairn's servers.
Your Dexcom password is checked once by the app, sent to the dock over an encrypted Bluetooth link, and stored encrypted on the dock. The app doesn't keep it, and it can't be read back out of the dock.
Only phones you pair by typing the code on the dock's screen can change its settings.
Questions
Does Cairn replace my CGM app or receiver?
No. Cairn is a secondary display. Its chimes are an extra alert, so keep your CGM app's alerts on, and use your CGM app or receiver for treatment decisions and to confirm readings.
Which CGMs does it work with?
At launch, Cairn reads from Dexcom Share. The CGM wearer needs Share turned on in their Dexcom app. Other sources may follow.
Will it wake me up?
It's designed to be heard across a bedroom. Lows and highs chime at the volume you choose, and quieter during quiet hours. Urgent low always sounds and gets louder if no one taps the dock. Cairn reads Dexcom Share every five minutes over Wi-Fi, so it can lag your CGM app; keep your CGM app's alerts on.
What happens if the Wi-Fi drops?
Cairn shows dashes and how long it's been since the last reading, and after 20 minutes it dims to white and chirps. It never shows an old number as if it were current.
Can a parent's phone get alerts too?
Yes. Up to four phones can be paired with one dock. Each paired phone within Bluetooth range gets the unplug and battery alerts.
Will my phone fit?
The top is sized for the largest current phones lying sideways in a thick case.
When can I buy one?
Cairn is in development. Join the waitlist and we'll email you once when it's available.
Be first to know.
One email when Cairn is available. Nothing else.